Weather forecasting with triple-prt

Weather radar technology has taken major steps forward in the past years. The advances, most importantly the use of dual-polarization, have been led by hardware manufacturers leaving the development of signal processing software lagging behind. Triple-PRT scheme making use of three different sampling intervals combined with dual-polarization offers a unique opportunity to dramatically improve the analysis of radar data. Eigenor has developed signal processing software that utilizes this opportunity and solves the challenges encountered with the new technology.

Capabilities and added-value


1. Adaptive ground and sea clutter removal

2. Separation of clutter even in demanding triple-PRT measurements


1. Measuring high velocities up to 60 m/s

2. Unique spectral feed for triple-PRT


1. Clutter detection and removal based on dual-polarization quantities

2. High-quality dual-polarization data even in areas tainted by clutter

Triple-PRT setup

An ordinary radar sends short pulses with a fixed interval between them, typically with a length of two milliseconds. Triple-PRT uses three different intervals in a pattern, providing a solution to the so-called Doppler dilemma. This increases the velocities that can be correctly measured, from roughly 6 m/s to 60 m/s without reducing the range.

No more Doppler snakes

Modern weather radar forecasting is moving from single-PRT technology to triple-PRT and dual-polarization radars. This enables measuring high wind velocities, but at the same time brings about problems related to reflectivity estimation. Eigenor WnD solves these issues by adaptively removing ground and sea clutterdetected by thorough analysis of signals from both polarization channels. Doppler snakes are now history, and the subsequent analysis can be carried out using top quality data. Additionally, all variables are captured in real time with one measurement, saving time and money.

Eigenor WnD utilizes full dual-polarization parameters, supporting this major enhancement in improving weather forecasting. It is the only available industrial standard software solution which provides a full set of standard analysis products for triple-PRT systems.

The method under the software released as a book

The triple-PRT method utilised in Eigenor WnD has been described and verified with the help of Finnish Meteorological Institute and University of Helsinki by vast number real C-band measurements in different weather conditions. The triple-PRT is a novel weather radar signal processing method and a scientific book has been released to explain and show the benefits of triple-PRT. You can download the table of contents and forewords of the book from here.

Enabling nowcasting

The capability to measure high wind speeds and to separate different layers of precipitation enables reliable short-term predictions and warnings of, for instance, sand storms or heavy rainfall. Nowcasting combined with modern communication technology allows for safety precautions even in rapidly developing conditions.

Key benefits for weather forecasting

  • Advanced clutter removal provides quality data for subsequent analysis
  • Accurate reflectivity values for rainfall estimates
  • Unambiguous wind speeds up to 60 m/s extend the scope and quality of useful data
  • Reliable velocity estimates to be used in weather models
  • Bird detection improved by unambiguous speed measurement
  • Complete set of dual-polarization products for classification (e.g. rain, hail, birds, insects)
  • Patented spectral analysis for sea clutter removal
  • Real-time operation enables nowcasting and surveillance applications
  • All observables captured in a single measurement enabling fast scanning

Customer statement

“Finnish Meteorological Institute has long experience in weather radar based services. It is at the leading edge of advanced utilization of modern methodologies in radar meteorology. Our recent experience with Eigenor data processing suggests that their new methods can meet our high product quality requirements. The triple-PRT based Doppler velocity folding seems to be reliable and accurate even in very strong winds. The adaptive clutter filtering offers excellent performance, prohibiting e.g. the erroneous impact of clutter filtering to reflectivity of rainfall, which is present in conventional systems.”


Jarmo Koistinen, Senior Research Scientist, Earth Observation,
Finnish Meteorological Institute